value能小於正常範圍最低值的人肯定本身有問題。這篇文章是找了不同值的各類人做的研究, 包含正常健康的人。
“normal” doesn’t necessarily equate to optimal if you’re interested in preventing disease.
Using a multivariable adjusted quadratic spline with HbA1c=5.2% as the cut-point, low and high HbA1c values were associated with an increased risk of all-cause mortality among individuals without diabetes.
Here is another article: